The vase arrived from Germany a few days ago.
I had recognized it as being a Meydam design rather than a Murano vase. It is a plum coloured sommerso with blue swirls around the inside. The sommerso pouch is encased in the Leerdam clear glass and has pinched shoulders. Below is the regular Leerdam ground pontil. I think it is an inverse of the "2-205" vase that you are seeing more of these days.
It is 12 x 11 x 5 cm (4.8" x 4.2" x 2").

"For 35 years (1949-1984) Meydam was head of design department at Leerdam. In this capacity he gave the post-war collection of the glass factory a recognizable face. He is responsible for a large number of designs for both utility glass (glass dinnerware, bowls, vases, etc.) and glass packaging. In addition, he designed numerous pieces of occasional glass: Leerdam Unica, Leerdam Serica and glass panels. He also designs for the ceramics industry, including the famous Black Princess for Regina.
Meydam continually searched for new forms and he designed many innovative items. Typical of his work is the simplicity of the design.
As an industrial designer and independent artist, he received many national and international awards and prizes. In 1952 he was the first Dutch designer at the Museum of Modern Art (New York) and won the "Good Design Award". After retirement in 1984 he continued on as an independent glass artist."